1. Field of the Invention
The invention relates to flux dams and more particularly to use of such flux dams in welding two workpieces together by electrically welding along a weld groove formed between the workpieces while adding flux to the groove to maintain a slag blanket over a pool of weld metal in the groove. Such welding is known generally as submerged arc welding. More particularly the invention relates to the use of a particular composition which is extrudable to define the flux dam by adhering a first wire of the composition on one side of the weld groove and a second wire of the composition on the other side of the weld groove.
2. Prior Art
Submerged arc welding is of course quite well known. In the past, copper strips or shoes have been clamped against the side of a vertical weld piece to extend slightly above the top thereof while the vertical weld piece has been abutted against the horizontal weld piece to define a weld groove between the two workpieces. The groove has then been welded electrically while flux has constantly been added thereto so that a slag blanket is maintained constantly over the pool of molten metal in the weld groove. The copper shoes have served to hold the slag blanket so that it will not escape over the top of the vertical workpiece. While the use of copper strips will often produce an adequate product and the copper strips will adequately retain the slag, certain problems exist with such a technique and these problems are being multiplied by modern developements in submerged arc welding. First, there is the cost of the copper shoes. Second, there is the necessity for clamping the shoes in place. Third, when the two workpieces being welded together have a curved rather than a straight surface the copper strips must be bent to match the surfaces and since copper will fatigue on constant bending and rebending this requires constant replacement of the copper strips. Fourth, computer controlled welding is becoming more popular whereby a sensor is used to sense the position of the weld groove and the weld electrode is guided along the groove by a feedback type of circuit. In this case the use of copper shoes is particularly disadvantageous since the shoes themselves tend to get in the way of the sensor and even more seriously the clamps for the copper shoes tend to get in the way of the sensor whereby it often becomes impossible to carry out automated submerged arc welding. Fifth, the copper shoes tend to stick to the welds.
It would clearly be advantageous to provide a utilizing a flux dam which could not suffer from the aforementioned disadvantages and which was also very inexpensive, easy to apply, easy to store and small to store. The present invention relates to just such a method.